The GMB union said that a long-serving employee had been suspended and will be represented by the union at the disciplinary hearing on 1 September – the day the new redundancy terms are due to come into force.

Maria Ludkin, the GMB’s legal affairs officer, told The Times: “I hope Marks & Spencer will realise they have over-reacted. It’s clear case of bullying. M&S has always been based upon its staff. It would be a shame to see that change.”

The high street giant wants to reduce the maximum payout that employees can receive from 70 weeks salary to 52 weeks. An average employee with 30 years’ service would see their potential payoff fall by £9,000 to £26,000.

Staff under the age of 40 would receive two weeks for every year, down from 2.5 weeks.

A M&S spokesperson told Personnel Today that the change was introduced done to update company policy, and was not a money-saving measure.